The present invention relates to fusion of pre-operative image data with intra-operative image data, and more particularly, to cardiac model based fusion of pre-operative computed tomography (CT) data and intra-operative C-arm CT data.
Minimally invasive transcatheter cardiac interventions are adopted rapidly, especially for high-risk patients, to treat a wide range of cardiovascular diseases, including endovascular stenting for coronary stenoses, valve repair and replacement, and cardiac arrhythmia ablation. Pre-operative imaging plays an important role in cardiac interventions for planning, simulation, and intra-operative visual guidance. Various imaging modalities, such as CT, magnetic resonance imaging (MRI), and ultrasound, may be used for different types of interventions. Pre-operative images often provide detailed delineation of cardiac structures (e.g., in CT or MRI) or cardiac motion information (e.g., cine MRI or real-time ultrasound). Accordingly, such pre-operative images are important for planning of the surgical procedure and simulation of the surgical outcome. Overlaying a cardiac model extracted from pre-operative images onto real-time fluoroscopic images provides valuable visual guidance during cardiac intervention surgeries. However, direct fusion of such a 3D model with an intra-operative fluoroscopic image (3D-to-2D registration) is difficult because the images are captured at different times, on different scanning machines, and sometimes from different cardiac phases. The procedure for directed 3D-to-2D fusion typically requires some amount of user interaction, and contrast agent injection is often required to highlight the target anatomy in the fluoroscopic image in order to facilitate the registration. However, due to side effects of contrast agent, such as renal failure, it is desirable to minimize and, if possible, completely avoid the use of contrast agent.